The present invention relates to a recording and reproducing apparatus having a simultaneous reproducing function in which the reproducing operation is conducted substantially simultaneously with the recording operation.
In the case of a video cassette recorder for a broadcasting station (hereinafter, referred to as "broadcasting VCR"), it is difficult in many cases to conduct the image recording over again. Therefore, a failure in recording must be prevented from occurring. In order to prevent such a failure from occurring, a broadcasting VCR must have a simultaneous reproducing function in which the recording operation and the operation of reproducing the recorded contents are conducted at the substantially same time, thereby enabling the recorded contents to be checked.
When such a simultaneous reproducing function is to be realized, there arises a problem in that, since components such as recording and reproducing heads which are proximately positioned, and recording and reproducing rotary-transformers which respectively transmit a signal to the heads operate simultaneously, crosstalk interference in which a recording signal is mixed into a weak reproduced signal must be suppressed to a level as low as possible. For example, a signal reproduced by a reproducing head is lower in level by about 70 dB than a recording signal supplied to a recording head. In order to prevent crosstalk interference in which a recording signal leaks into a reproduced signal from occurring, when the level allowance of a crosstalk signal with respect to a reproduced signal is -30 dB, recording and reproducing signal levels must be separated from each other by 100 dB or more.
In the prior art, as a technique for suppressing crosstalk interference from a recording signal to a reproduced signal, a method is known in which recording and reproducing rotary-transformers are separately positioned, thereby reducing crosstalk between the rotary-transformers (for example, Japanese Unexamined Patent Publications (Tokkai) Nos. Hei 3-34103, Hei 3-232101, and Hei 3-286403) Moreover, a method is known in which a reproducing head is electromagnetically shielded from a recording head by an electrically conductive stuff or the like (for example, Japanese Unexamined Patent Publication (Tokkai) No. Hei 2-198002).
Recently, there is a demand for a small light broadcasting VCR with the largely reduced size of a rotary cylinder unit. When such a small rotary cylinder unit is used, however, it is difficult to separately position recording and reproducing rotary-transformers or electromagnetically shield a reproducing head from a recording head by an electrically conductive stuff or a magnetic material as in the above-mentioned cases of the prior art. Even if such a countermeasure can be done, the distance between the recording and reproducing heads, the distance between the recording and reproducing rotary-transformers, as well as the distances between wirings for a recording signal and those for a reproduced signal among various portions must be made short, with the result that it is very difficult to separate the recording and reproducing signal levels from each other by 100 dB or more. In the field of the technology therefore, it is a problem to realize a small VCR having a simultaneous reproducing function